Microformats Wiki - User contributions [en]

hcard-brainstorming

2006-05-24T02:43:28Z

Satoru: /* ISO6709 */

<h1> hCard Brainstorming </h1>
This page is for brainstorming about various uses and details of [[hcard|hCard]].

__TOC__

== Authors ==
* [http://suda.co.uk/ Brian Suda]
* [http://tantek.com/log/ Tantek Çelik], [http://technorati.com Technorati, Inc]

== Contributors ==
* [[User:Atamido|Atamido]]
* [[User:ChrisMessina|ChrisMessina]]
* [[User:DimitriGlazkov|DimitriGlazkov]]
* ...
* ... and many others

== Problems Being Solved ==

Some of the problems that [[hcard|hCard]] helps to solve:

* having to enter business cards that go out of date (subscribe to someone's syndicated [[hcard|hCard]] instead).
* annoying "update your contact info" email from various centralized contact info services

== Examples ==

* See [[hcard-examples]], which provides several illustrative instructive examples, as well as 1:1 hCard examples for each example in [http://www.ietf.org/rfc/rfc2426.txt RFC 2426].

=== Using RFC2806 with hCard ===

[http://www.ietf.org/rfc/rfc2806.txt RFC 2806] defines the telephone scheme "tel:", "fax:" and "modem:" to handle phone communications with URIs in the same way, "mailto:" is defined for email. It's part of the list or registered schemes by IANA : [http://www.iana.org/assignments/uri-schemes Uniform Resource Identifier (URI) SCHEMES]

<pre><nowiki>
tel telephone [RFC2806]
fax fax [RFC2806]
modem modem [RFC2806]
</nowiki></pre>

It is practical to write your tel number like this.

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">+1-919-555-7878</a>
</nowiki></pre>

or even

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">Mr Smith's phone</a>
</nowiki></pre>

You can add support for "tel:" to your desktop and to your browser

* For Gnome, edit ~/.gnome/Gnome and add something to the URL Handlers section. (Dan Connolly uses this to get galeon to launch telnum from [http://dev.w3.org/cvsweb/2001/telagent/ telagent sources] for tel URIs)
* In Mozilla, [http://dizzy.mozdev.org/ Dizzy]
* In Internet Explorer, [http://msdn.microsoft.com/workshop/networking/pluggable/overview/overview.asp Asynchronous Pluggable Protocols]

On the CSS front… You could for example add automagically an icon. I have put the property !important for those who wants to add it to their own stylesheet in their browsers, so they know type of links when browsing.

<pre><nowiki>
a[href^="tel:"]:before {
content: '\260f ' !important;
padding-left: 20px !important; }

a[href^="mailto:"]:before {
content: '\2709 ' !important;
padding-left: 20px !important; }
</nowiki></pre>

== Encoding "modern" attributes ==

Since vCard was first established, various interactive communication technologies and addressing schemes have been widely adopted. Although there aren't specific properties for these technologies / addressing schemes, they can be captured as URLs or email addresses.

This has now been written up for the most part. See:

http://microformats.org/wiki/hcard-examples#New_Types_of_Contact_Info

Still to be addressed:

* iChat mac.com addresses, simply store "@mac.com" email addresses, e.g.
** <code><a class="email" href="mailto:steve@mac.com">...</code>
* MSN Instant Messenger, you can simple store "@hotmail.com" or "@msn.com" or "@passport.com" email addresses.
* Internet Relay Chat (IRC), use "irc:" URLs.

== CSS Styles ==
Not only can you create semantics with the hCard values, but you can add CSS styles to them as well. You are free to style the terms in any way you want, but here we can list a few ideas for how to style terms.

If you want to encode hCard data, but do NOT want to display it in the HTML code, then you can hide that tag in CSS with the following code:
<pre><nowiki>
Hidden Data
</nowiki></pre>
Transforming applications will still find the data and use it when converting hCards to vCards.

== Auto-Discovery ==
There is currently a debate over the best way to add an auto discovery link to your HTML to extract the vCard.

On the page with the hCard encoding, the best link would be as follows:
<code><nowiki> <link rel="alternate" type="text/vcard" href="..." /> </nowiki></code>
this HTML page is an alternate view of the vCard.

[[User:EtanWexler|EtanWexler]] disagrees with the value of the “type” attribute. The [http://www.iana.org/ Internet Assigned Numbers Authority] has no registration for a “text/vcard” type. The [http://www.iana.org/assignments/media-types/text/ registered and appropriate type] for vCard entities is “text/directory”, as defined in Internet RFC 2425, “[http://www.rfc-editor.org/rfc/rfc2425.txt A MIME Content-Type for Directory Information]”. RFC 2426, “[http://www.rfc-editor.org/rfc/rfc2425.txt vCard MIME Directory Profile]”, specifies the vCard profile for “text/directory” entities, which profile the MIME/HTTP header field “Content-Type” would indicate with a “profile” parameter whose value is “VCARD”. It is unclear whether the HTML/XHTML “type” attribute allows values with parameters. On 2004-05-23, [http://bjoern.hoehrmann.de/ Björn Höhrmann] sent to the [http://www.w3.org/2002/05/html/charter HTML Working Group] a [http://www.w3.org/mid/40ccdc4d.97400945@smtp.bjoern.hoehrmann.de request for clarification] on the issue.

When on a different page, referencing that encoded page in the href would ''not'' be an alternate view of the current page. So a different rel type must be established to decribe that relationship. The ideas vary from specific to vague. The list and categories follow:
<pre><nowiki>
rel="contactinfo"
rel="profile"
rel="author"
rel='PIM'
rel='person'
rel='about'
rel='contact'
rel='hcard'
rel='microformat'
</nowiki></pre>
Example of mixing two rel types to a single page.
rel="hcard xfn"

Note: using rel="vcard" indicates a link directly to a vCard. If the document links to an hCard instead, the indication is untrue and inappropriate.

=== Auto-Discovery for XFN ===

An author will typically their XFN information on a specific page, rather than all pages. In particular, a specific page separate from the home page of their blog, and thus it would be useful to have an explicit rel value to assist in auto-discovery of XFN information.

This was suggested by Jens Alfke on 20050606 at the WWDC blogger's dinner.

== geo improvements ==

These improvements apply to both [[geo]] and [[hcard|hCard]].

I (Tantek) have seen examples of where there is a human viewable/clickable presentation of a point on a map, and the desire to include the machine readable geo information with the same element, e.g. something like:

<pre><nowiki>
<abbr class="geo" title="machine-readable-geo-info">
human readable/clickable point on a map
</abbr>
</nowiki></pre>

But to do this we must specify a syntax for putting both the latitude and longitude into the title attribute as the machine-readable-geo-info.

Fortunately, there already is a syntax for that, in vCard RFC 2426 3.4.2:
<pre>
Type value: A single structured value consisting of two float values
separated by the SEMI-COLON character (ASCII decimal 59).

Type special notes: This type specifies information related to the
global position of the object associated with the vCard. The value
specifies latitude and longitude, in that order (i.e., "LAT LON"
ordering).

...

Type example:

GEO:37.386013;-122.082932
</pre>

Thus:
<pre><nowiki>
<abbr class="geo" title="37.386013;-122.082932">
Mountain View, CA
</abbr>
</nowiki></pre>

I think this is pretty much a no-brainer, because the rules for parsing "geo" are simply altered to:

=== latitude longitude shorthand ===

If a "geo" property lacks explicit "latitude" and "longitude" subproperties, then the "geo" property is treated like any other string property (e.g. following rules for parsing <code><nowiki><abbr title></nowiki></code>, <code><nowiki><img alt></nowiki></code> etc.), where that string value has the same literal syntax as specified in RFC 2426 section 3.4.2: single structured value consisting of two float values separated by the SEMI-COLON character (ASCII decimal 59), specifying latitude and longitude, in that order.

=== geo links ===

In addition, people may publish Google Maps links like this:

<a href="http://maps.google.com/maps?q=37.386013+-122.082932">this spot</a>

(N.B. I tried and failed to get Yahoo Maps and local to do something intelligent with both "37.386013;-122.082932" and "37.386013 -122.082932").

Is it worth permitting this to be a geo as well?

I'm raising this to make sure it is considered.

However, my first guess is NO for two reasons.

# No such examples in the wild have been documented or seen as of yet (I certainly haven't seen any).
# It would involve additional parsing requirements which are almost certainly going to be site/domain specific, and encoding a particular site's query parameter syntax into a format seems like a bad idea (against principle of decentralization).

This could be mitigated if mapping services would simply accept the literal vCard GEO syntax "37.386013;-122.082932", e.g. http://maps.google.com/maps?q=37.386013;-122.082932 (which currently doesn't work) then we could make a simple rule such as for hyperlinks, parse the href attribute for a geo value at the end of the href, delimited before the value by a "=" (or perhaps "/" for services that use friendlier URLs).

=== altitude ===

Some folks have asked for "altitude" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.

=== radius/zoom ===

Kevin Marks has asked for "radius" or "zoom" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.
=== ISO6709 ===
There is a description method for geographic coordinates named [http://en.wikipedia.org/wiki/ISO_6709 ISO6709] though some differs from the notation of vCard.
It can describe latitude and the longitude. Height is optional.
If ISO6709 is used, it is likely to be able to write as follows.
<pre><nowiki>
examples
<abbr class="geo" title="+37.386013-122.082932/">
Mountain View, CA
</abbr>

<abbr class="geo" title="+275916+0865640+8850/">
Mount Everest
</abbr>

</nowiki></pre>

== Issues with vCard Applications ==
See [[vcard-implementations]].

== Open Questions ==

Q: since many of the components would be using CSS classes for encoding data, it is possible to MIX two different profiles. (e.g. hCard and XFN) There are no real constraints on where/how to enforce class names, these are based on the html profile, since it is difficult to associate the text within the attribute to a specific profile.

<pre><nowiki>
...
<a href="mailto:joe.smith@example.com" class="fn" rel="met">Joe Smith</a>
...
</nowiki></pre>

-- [http://suda.co.uk/ Brian Suda]

Q: Preserving White space? Should the transforming applications preserve extra white space characters? For example:
<pre><nowiki>
<a href="http://mywebsite.com/" class="fn n">
John
Q.
Public
</a>
</nowiki></pre>

When transformed into a vCard, the N property will pick apart the span tags and create the value for N correctly seperated by colons. The FN property will take a string and simply display it. There are two possible renderings for FN:
<pre><nowiki>
John Q. Public

John
Q.
Public
</nowiki></pre>

Either the white-space is preserved or it is not. Which should the transforming applications render?

-- [http://suda.co.uk/ Brian Suda]

A: The parsing application should follow the white space collapsing rules of the mime type it retrieves. I.e. if it retrieves a "text/html" document, it should do HTML white space collapsing.

-- [http://tantek.com/log/ Tantek]

Many of the Questions and Answers are relevant to both ["hCal"] and hCard.

Q: Would it be appropriate to wrap the name of the vCard owner with <dfn/>? This may give the hCard some added semantic value in the XHTML document.
<pre><nowiki>



<a class="internet" href="mailto:jfriday@host.com">
<dfn>
Joe Friday
</dfn>
</a>

+1-919-555-7878
Area Administrator, Assistant


</nowiki></pre>
-- [http://www.ben-ward.co.uk/ Ben Ward]

== Applications ==
Applications that are hCard aware or can convert hCard to vCard formats.

=== Copy hCards favelet(s) ===
* I think a Favelet would work nicely here. When you find a page that is hCard friendly, you click the favlet and you get yourself a vCard. This is done! See X2V in the implementations section of the [[hcard|hCard]] spec.

=== Distributed Commentor Icons ===

* See [http://thedredge.org/2005/06/using-hcards-in-your-blog/ using hCards in your blog] for an example of hCards used for comment authors (commentors). The system used there, "Gravatars", is a centralized site that serves commentor icons that requires login etc.

What if we gave each commentor the option of hosting their own icon?

A distributed commentor icon implementation could work like this:

# Given the URL of a commentor, look for an <code><address></code> element with classname of "vcard" at the commentor's URL. The <code><address></code> element is supposed to be the contact information for the page (see [[hcard-faq|hCard FAQ]] for more info), so this makes sense.
# Next, look for the first element inside that hcard that has a classname of "logo".
# Hopefully that element is an <code><img></code>, and if so, use its src to get the commentor's icon.
# Presto. You've got distributed commentor icons!

== Spam prevention ==
hCard uses <code>mailto:</code> links, and therefore
it automatically "inherits" the disadvantage of <code>mailto:</code> links:
These links can be easily detected by emails spiders (used by spammers).

There are ways to prevent email address detection by simple email spiders, while
still retaining full compatibility with (X)HTML applications.
One common way is to "encode" the the "m" of "mail" and "@" with character entities:

Example of the original link:
<pre><nowiki>
<a class="email" href="mailto:john.smith@example.com">john.smith@example.com</a>
</nowiki></pre>

Example of the "encoded" link:
<pre><nowiki>
<a class="e&#109;ail" href="&#109;ailto:john.smith&#064;example.com">john.smith&#064;example.com</a>
</nowiki></pre>

Simple email spiders which do not do character entity decoding will therefore not be able to find your email address.

''Note:'' Perhaps there are or will be email spiders which can decode entities, so the this technique will only help with some (cheap) email spiders.
(See also: http://rbach.priv.at/Misc/2005/EmailSpiderTest)

== Tutorials ==
* How to hCard encode entries in Popular blog software.
* Good reasons to publish your hCard
** as a business, get people to put you in their address book so they'll find you later
** as a business with an email list, get people to add you (with email address) to their address book so that your email list works via whitelisting via the address book.

== Parsing ==
See separate [[hcard-parsing|hCard parsing]] page.

== Post vCard additions ==

Some have found vCard to be limiting in terms of the data/properties/fields they want to express in contact information. Some implementations use vCard extensions to express such information.

This section is for documentation of such suggested additions. Note, we will require empirical evidence of actual *real world* examples on the Web of people publishing this information as part of contact information, before considering such additions/extensions.

* altitude. From [[hcard-issues]].
** No evidence provided that contact information on the Web publishes this information.

== TODO ==

* The [[hcard-profile]] needs verification and perhaps a URL for retrieving the actual XMDP, rather than as <pre> text on a wiki page.
* Complete translating the examples from the vCard spec into hCard, and place them on a separate hCard examples page.
* Create a "rich" but realistic hCard example, say for example for a salesperson, who wants to put a whole bunch of contact information on their website in order to be found/contacted easily.
* Provide examples of how to encode instant messaging (IM) accounts. Figure out what would the mailto: or aim: URL in hCard look like in vCard. And take a look at what vCard applications do today with IM addresses.

== References ==
=== Normative References ===
* [http://www.ietf.org/rfc/rfc2426.txt RFC 2426] vCard RFC
* [http://www.ietf.org/rfc/rfc2397 RFC 2397] data URI RFC
* [http://gmpg.org/xmdp/ XMDP]
=== Informative References ===
* [http://www.imc.org/pdi/ Personal Data Interchange (PDI) at the Internet Mail Consortium]
* [http://tantek.com/log/2004/07.html#d27t1049 Markup language design notes]
* [http://tantek.com/log/2002/12.html#L20021216t2238 A Touch of Class]

== Other Implementations/Ideas ==
* [http://www.w3.org/TR/2001/NOTE-vcard-rdf-20010222/ Representing vCard Objects in RDF/XML] This could allow conversion of vCard data from XHTML to RDF and from RDF to XHTML
* It would also be possible to convert XFN and hCard to FoaF and back.

== Accepted Suggestions ==

=== Encoding Company data as a Business Card (proposal) ===

( Accepted: http://microformats.org/wiki/hcard#Organization_Contact_Info )

In the wild there are several hCards that do not currently validate because they are businesses that have omitted the "fn" property in favor of the "org" property.

Proposal: hCards representing a business or organization MUST set fn AND org to the same value. Parsers may then use this equivalence, if detected, to treat an hCard as the contact info for a business or organization rather than an individual.

Note that [http://microformats.org/wiki/vcard-implementations#organization_vs._individual Apple Address Book supports this semantic when importing vCards].

See the [http://technorati.com/about/contact.html Technorati Contact Info] for an example.

=== Implied "FN and N" Optimization (proposal) ===

Right now a parser first looks for an "n" element.

And then if no "n" is present, look for an "fn" element to use to imply an "n" element per the "implied n property" rules in the spec.

BACKGROUND:

Due to the prevalence of the use of "nicknames" or "handles" on the Web, in actual content published on the Web (e.g. authors of reviews), there has been a discussion about adding a "fn" shortcut to the "n" shortcut that used the "nickname" as a fallback.

PROPOSAL:

We should consider adding one more implied optimization after the steps documented above and that is:

If no "fn" is present either, then look for a "nickname" element to use to imply both the "fn", and the "n/given-name", leaving the "n/family-name" as empty.

This would enable "nickname" only hCards for denoting and individual on a website, which is quite common on blogs and reviews published on the Web.
* +1 [[User:Atamido|Atamido]]
* +1 [[User:ChrisMessina|ChrisMessina]] - note: multiple alternate nicknames should also be allowed
* +1 [[User:DimitriGlazkov|DimitriGlazkov]]

== Rejected Suggestions ==

Suggestion: ''The use of class="url" on an <a> tag to represent an hCard URL property is redundant. By virtue of the <a> tag you know this is a URL.''

Rejected. This is a bad suggestion because although it appears to reduce redunancy and keep things cleaner, it also creates a few problems. Without explicitly noting that this is a URL then any <a> tags within a 'vcard' would be considered a URL, for example:
<pre><nowiki>

...
<ul class="categories">
<li><a href="http://w3c.org">W3C</a></li>
</ul>
...

</nowiki></pre>

There is no way to "turn-off" the encoding of the W3C URL, whereas if "url" needed to be explicitly listed in the class attribute list, then by NOT listing it you could effectively turn it off.

hcard-brainstorming

2006-05-24T02:37:55Z

Satoru: /* ISO6709 */

<h1> hCard Brainstorming </h1>
This page is for brainstorming about various uses and details of [[hcard|hCard]].

__TOC__

== Authors ==
* [http://suda.co.uk/ Brian Suda]
* [http://tantek.com/log/ Tantek Çelik], [http://technorati.com Technorati, Inc]

== Contributors ==
* [[User:Atamido|Atamido]]
* [[User:ChrisMessina|ChrisMessina]]
* [[User:DimitriGlazkov|DimitriGlazkov]]
* ...
* ... and many others

== Problems Being Solved ==

Some of the problems that [[hcard|hCard]] helps to solve:

* having to enter business cards that go out of date (subscribe to someone's syndicated [[hcard|hCard]] instead).
* annoying "update your contact info" email from various centralized contact info services

== Examples ==

* See [[hcard-examples]], which provides several illustrative instructive examples, as well as 1:1 hCard examples for each example in [http://www.ietf.org/rfc/rfc2426.txt RFC 2426].

=== Using RFC2806 with hCard ===

[http://www.ietf.org/rfc/rfc2806.txt RFC 2806] defines the telephone scheme "tel:", "fax:" and "modem:" to handle phone communications with URIs in the same way, "mailto:" is defined for email. It's part of the list or registered schemes by IANA : [http://www.iana.org/assignments/uri-schemes Uniform Resource Identifier (URI) SCHEMES]

<pre><nowiki>
tel telephone [RFC2806]
fax fax [RFC2806]
modem modem [RFC2806]
</nowiki></pre>

It is practical to write your tel number like this.

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">+1-919-555-7878</a>
</nowiki></pre>

or even

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">Mr Smith's phone</a>
</nowiki></pre>

You can add support for "tel:" to your desktop and to your browser

* For Gnome, edit ~/.gnome/Gnome and add something to the URL Handlers section. (Dan Connolly uses this to get galeon to launch telnum from [http://dev.w3.org/cvsweb/2001/telagent/ telagent sources] for tel URIs)
* In Mozilla, [http://dizzy.mozdev.org/ Dizzy]
* In Internet Explorer, [http://msdn.microsoft.com/workshop/networking/pluggable/overview/overview.asp Asynchronous Pluggable Protocols]

On the CSS front… You could for example add automagically an icon. I have put the property !important for those who wants to add it to their own stylesheet in their browsers, so they know type of links when browsing.

<pre><nowiki>
a[href^="tel:"]:before {
content: '\260f ' !important;
padding-left: 20px !important; }

a[href^="mailto:"]:before {
content: '\2709 ' !important;
padding-left: 20px !important; }
</nowiki></pre>

== Encoding "modern" attributes ==

Since vCard was first established, various interactive communication technologies and addressing schemes have been widely adopted. Although there aren't specific properties for these technologies / addressing schemes, they can be captured as URLs or email addresses.

This has now been written up for the most part. See:

http://microformats.org/wiki/hcard-examples#New_Types_of_Contact_Info

Still to be addressed:

* iChat mac.com addresses, simply store "@mac.com" email addresses, e.g.
** <code><a class="email" href="mailto:steve@mac.com">...</code>
* MSN Instant Messenger, you can simple store "@hotmail.com" or "@msn.com" or "@passport.com" email addresses.
* Internet Relay Chat (IRC), use "irc:" URLs.

== CSS Styles ==
Not only can you create semantics with the hCard values, but you can add CSS styles to them as well. You are free to style the terms in any way you want, but here we can list a few ideas for how to style terms.

If you want to encode hCard data, but do NOT want to display it in the HTML code, then you can hide that tag in CSS with the following code:
<pre><nowiki>
Hidden Data
</nowiki></pre>
Transforming applications will still find the data and use it when converting hCards to vCards.

== Auto-Discovery ==
There is currently a debate over the best way to add an auto discovery link to your HTML to extract the vCard.

On the page with the hCard encoding, the best link would be as follows:
<code><nowiki> <link rel="alternate" type="text/vcard" href="..." /> </nowiki></code>
this HTML page is an alternate view of the vCard.

[[User:EtanWexler|EtanWexler]] disagrees with the value of the “type” attribute. The [http://www.iana.org/ Internet Assigned Numbers Authority] has no registration for a “text/vcard” type. The [http://www.iana.org/assignments/media-types/text/ registered and appropriate type] for vCard entities is “text/directory”, as defined in Internet RFC 2425, “[http://www.rfc-editor.org/rfc/rfc2425.txt A MIME Content-Type for Directory Information]”. RFC 2426, “[http://www.rfc-editor.org/rfc/rfc2425.txt vCard MIME Directory Profile]”, specifies the vCard profile for “text/directory” entities, which profile the MIME/HTTP header field “Content-Type” would indicate with a “profile” parameter whose value is “VCARD”. It is unclear whether the HTML/XHTML “type” attribute allows values with parameters. On 2004-05-23, [http://bjoern.hoehrmann.de/ Björn Höhrmann] sent to the [http://www.w3.org/2002/05/html/charter HTML Working Group] a [http://www.w3.org/mid/40ccdc4d.97400945@smtp.bjoern.hoehrmann.de request for clarification] on the issue.

When on a different page, referencing that encoded page in the href would ''not'' be an alternate view of the current page. So a different rel type must be established to decribe that relationship. The ideas vary from specific to vague. The list and categories follow:
<pre><nowiki>
rel="contactinfo"
rel="profile"
rel="author"
rel='PIM'
rel='person'
rel='about'
rel='contact'
rel='hcard'
rel='microformat'
</nowiki></pre>
Example of mixing two rel types to a single page.
rel="hcard xfn"

Note: using rel="vcard" indicates a link directly to a vCard. If the document links to an hCard instead, the indication is untrue and inappropriate.

=== Auto-Discovery for XFN ===

An author will typically their XFN information on a specific page, rather than all pages. In particular, a specific page separate from the home page of their blog, and thus it would be useful to have an explicit rel value to assist in auto-discovery of XFN information.

This was suggested by Jens Alfke on 20050606 at the WWDC blogger's dinner.

== geo improvements ==

These improvements apply to both [[geo]] and [[hcard|hCard]].

I (Tantek) have seen examples of where there is a human viewable/clickable presentation of a point on a map, and the desire to include the machine readable geo information with the same element, e.g. something like:

<pre><nowiki>
<abbr class="geo" title="machine-readable-geo-info">
human readable/clickable point on a map
</abbr>
</nowiki></pre>

But to do this we must specify a syntax for putting both the latitude and longitude into the title attribute as the machine-readable-geo-info.

Fortunately, there already is a syntax for that, in vCard RFC 2426 3.4.2:
<pre>
Type value: A single structured value consisting of two float values
separated by the SEMI-COLON character (ASCII decimal 59).

Type special notes: This type specifies information related to the
global position of the object associated with the vCard. The value
specifies latitude and longitude, in that order (i.e., "LAT LON"
ordering).

...

Type example:

GEO:37.386013;-122.082932
</pre>

Thus:
<pre><nowiki>
<abbr class="geo" title="37.386013;-122.082932">
Mountain View, CA
</abbr>
</nowiki></pre>

I think this is pretty much a no-brainer, because the rules for parsing "geo" are simply altered to:

=== latitude longitude shorthand ===

If a "geo" property lacks explicit "latitude" and "longitude" subproperties, then the "geo" property is treated like any other string property (e.g. following rules for parsing <code><nowiki><abbr title></nowiki></code>, <code><nowiki><img alt></nowiki></code> etc.), where that string value has the same literal syntax as specified in RFC 2426 section 3.4.2: single structured value consisting of two float values separated by the SEMI-COLON character (ASCII decimal 59), specifying latitude and longitude, in that order.

=== geo links ===

In addition, people may publish Google Maps links like this:

<a href="http://maps.google.com/maps?q=37.386013+-122.082932">this spot</a>

(N.B. I tried and failed to get Yahoo Maps and local to do something intelligent with both "37.386013;-122.082932" and "37.386013 -122.082932").

Is it worth permitting this to be a geo as well?

I'm raising this to make sure it is considered.

However, my first guess is NO for two reasons.

# No such examples in the wild have been documented or seen as of yet (I certainly haven't seen any).
# It would involve additional parsing requirements which are almost certainly going to be site/domain specific, and encoding a particular site's query parameter syntax into a format seems like a bad idea (against principle of decentralization).

This could be mitigated if mapping services would simply accept the literal vCard GEO syntax "37.386013;-122.082932", e.g. http://maps.google.com/maps?q=37.386013;-122.082932 (which currently doesn't work) then we could make a simple rule such as for hyperlinks, parse the href attribute for a geo value at the end of the href, delimited before the value by a "=" (or perhaps "/" for services that use friendlier URLs).

=== altitude ===

Some folks have asked for "altitude" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.

=== radius/zoom ===

Kevin Marks has asked for "radius" or "zoom" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.
=== ISO6709 ===
There is a description method for geographic coordinates named [http://en.wikipedia.org/wiki/ISO_6709 ISO6709] though some differs from the notation of vCard.
It can describe latitude and the longitude. Height is optional.
If ISO6709 is used, it is likely to be able to write as follows.
<pre><nowiki>
examples
<abbr class="geo" title="+37.386013-122.082932/">
Mountain View, CA
</abbr>
</nowiki></pre>

== Issues with vCard Applications ==
See [[vcard-implementations]].

== Open Questions ==

Q: since many of the components would be using CSS classes for encoding data, it is possible to MIX two different profiles. (e.g. hCard and XFN) There are no real constraints on where/how to enforce class names, these are based on the html profile, since it is difficult to associate the text within the attribute to a specific profile.

<pre><nowiki>
...
<a href="mailto:joe.smith@example.com" class="fn" rel="met">Joe Smith</a>
...
</nowiki></pre>

-- [http://suda.co.uk/ Brian Suda]

Q: Preserving White space? Should the transforming applications preserve extra white space characters? For example:
<pre><nowiki>
<a href="http://mywebsite.com/" class="fn n">
John
Q.
Public
</a>
</nowiki></pre>

When transformed into a vCard, the N property will pick apart the span tags and create the value for N correctly seperated by colons. The FN property will take a string and simply display it. There are two possible renderings for FN:
<pre><nowiki>
John Q. Public

John
Q.
Public
</nowiki></pre>

Either the white-space is preserved or it is not. Which should the transforming applications render?

-- [http://suda.co.uk/ Brian Suda]

A: The parsing application should follow the white space collapsing rules of the mime type it retrieves. I.e. if it retrieves a "text/html" document, it should do HTML white space collapsing.

-- [http://tantek.com/log/ Tantek]

Many of the Questions and Answers are relevant to both ["hCal"] and hCard.

Q: Would it be appropriate to wrap the name of the vCard owner with <dfn/>? This may give the hCard some added semantic value in the XHTML document.
<pre><nowiki>



<a class="internet" href="mailto:jfriday@host.com">
<dfn>
Joe Friday
</dfn>
</a>

+1-919-555-7878
Area Administrator, Assistant


</nowiki></pre>
-- [http://www.ben-ward.co.uk/ Ben Ward]

== Applications ==
Applications that are hCard aware or can convert hCard to vCard formats.

=== Copy hCards favelet(s) ===
* I think a Favelet would work nicely here. When you find a page that is hCard friendly, you click the favlet and you get yourself a vCard. This is done! See X2V in the implementations section of the [[hcard|hCard]] spec.

=== Distributed Commentor Icons ===

* See [http://thedredge.org/2005/06/using-hcards-in-your-blog/ using hCards in your blog] for an example of hCards used for comment authors (commentors). The system used there, "Gravatars", is a centralized site that serves commentor icons that requires login etc.

What if we gave each commentor the option of hosting their own icon?

A distributed commentor icon implementation could work like this:

# Given the URL of a commentor, look for an <code><address></code> element with classname of "vcard" at the commentor's URL. The <code><address></code> element is supposed to be the contact information for the page (see [[hcard-faq|hCard FAQ]] for more info), so this makes sense.
# Next, look for the first element inside that hcard that has a classname of "logo".
# Hopefully that element is an <code><img></code>, and if so, use its src to get the commentor's icon.
# Presto. You've got distributed commentor icons!

== Spam prevention ==
hCard uses <code>mailto:</code> links, and therefore
it automatically "inherits" the disadvantage of <code>mailto:</code> links:
These links can be easily detected by emails spiders (used by spammers).

There are ways to prevent email address detection by simple email spiders, while
still retaining full compatibility with (X)HTML applications.
One common way is to "encode" the the "m" of "mail" and "@" with character entities:

Example of the original link:
<pre><nowiki>
<a class="email" href="mailto:john.smith@example.com">john.smith@example.com</a>
</nowiki></pre>

Example of the "encoded" link:
<pre><nowiki>
<a class="e&#109;ail" href="&#109;ailto:john.smith&#064;example.com">john.smith&#064;example.com</a>
</nowiki></pre>

Simple email spiders which do not do character entity decoding will therefore not be able to find your email address.

''Note:'' Perhaps there are or will be email spiders which can decode entities, so the this technique will only help with some (cheap) email spiders.
(See also: http://rbach.priv.at/Misc/2005/EmailSpiderTest)

== Tutorials ==
* How to hCard encode entries in Popular blog software.
* Good reasons to publish your hCard
** as a business, get people to put you in their address book so they'll find you later
** as a business with an email list, get people to add you (with email address) to their address book so that your email list works via whitelisting via the address book.

== Parsing ==
See separate [[hcard-parsing|hCard parsing]] page.

== Post vCard additions ==

Some have found vCard to be limiting in terms of the data/properties/fields they want to express in contact information. Some implementations use vCard extensions to express such information.

This section is for documentation of such suggested additions. Note, we will require empirical evidence of actual *real world* examples on the Web of people publishing this information as part of contact information, before considering such additions/extensions.

* altitude. From [[hcard-issues]].
** No evidence provided that contact information on the Web publishes this information.

== TODO ==

* The [[hcard-profile]] needs verification and perhaps a URL for retrieving the actual XMDP, rather than as <pre> text on a wiki page.
* Complete translating the examples from the vCard spec into hCard, and place them on a separate hCard examples page.
* Create a "rich" but realistic hCard example, say for example for a salesperson, who wants to put a whole bunch of contact information on their website in order to be found/contacted easily.
* Provide examples of how to encode instant messaging (IM) accounts. Figure out what would the mailto: or aim: URL in hCard look like in vCard. And take a look at what vCard applications do today with IM addresses.

== References ==
=== Normative References ===
* [http://www.ietf.org/rfc/rfc2426.txt RFC 2426] vCard RFC
* [http://www.ietf.org/rfc/rfc2397 RFC 2397] data URI RFC
* [http://gmpg.org/xmdp/ XMDP]
=== Informative References ===
* [http://www.imc.org/pdi/ Personal Data Interchange (PDI) at the Internet Mail Consortium]
* [http://tantek.com/log/2004/07.html#d27t1049 Markup language design notes]
* [http://tantek.com/log/2002/12.html#L20021216t2238 A Touch of Class]

== Other Implementations/Ideas ==
* [http://www.w3.org/TR/2001/NOTE-vcard-rdf-20010222/ Representing vCard Objects in RDF/XML] This could allow conversion of vCard data from XHTML to RDF and from RDF to XHTML
* It would also be possible to convert XFN and hCard to FoaF and back.

== Accepted Suggestions ==

=== Encoding Company data as a Business Card (proposal) ===

( Accepted: http://microformats.org/wiki/hcard#Organization_Contact_Info )

In the wild there are several hCards that do not currently validate because they are businesses that have omitted the "fn" property in favor of the "org" property.

Proposal: hCards representing a business or organization MUST set fn AND org to the same value. Parsers may then use this equivalence, if detected, to treat an hCard as the contact info for a business or organization rather than an individual.

Note that [http://microformats.org/wiki/vcard-implementations#organization_vs._individual Apple Address Book supports this semantic when importing vCards].

See the [http://technorati.com/about/contact.html Technorati Contact Info] for an example.

=== Implied "FN and N" Optimization (proposal) ===

Right now a parser first looks for an "n" element.

And then if no "n" is present, look for an "fn" element to use to imply an "n" element per the "implied n property" rules in the spec.

BACKGROUND:

Due to the prevalence of the use of "nicknames" or "handles" on the Web, in actual content published on the Web (e.g. authors of reviews), there has been a discussion about adding a "fn" shortcut to the "n" shortcut that used the "nickname" as a fallback.

PROPOSAL:

We should consider adding one more implied optimization after the steps documented above and that is:

If no "fn" is present either, then look for a "nickname" element to use to imply both the "fn", and the "n/given-name", leaving the "n/family-name" as empty.

This would enable "nickname" only hCards for denoting and individual on a website, which is quite common on blogs and reviews published on the Web.
* +1 [[User:Atamido|Atamido]]
* +1 [[User:ChrisMessina|ChrisMessina]] - note: multiple alternate nicknames should also be allowed
* +1 [[User:DimitriGlazkov|DimitriGlazkov]]

== Rejected Suggestions ==

Suggestion: ''The use of class="url" on an <a> tag to represent an hCard URL property is redundant. By virtue of the <a> tag you know this is a URL.''

Rejected. This is a bad suggestion because although it appears to reduce redunancy and keep things cleaner, it also creates a few problems. Without explicitly noting that this is a URL then any <a> tags within a 'vcard' would be considered a URL, for example:
<pre><nowiki>

...
<ul class="categories">
<li><a href="http://w3c.org">W3C</a></li>
</ul>
...

</nowiki></pre>

There is no way to "turn-off" the encoding of the W3C URL, whereas if "url" needed to be explicitly listed in the class attribute list, then by NOT listing it you could effectively turn it off.

hcard-brainstorming

2006-05-24T02:37:03Z

Satoru: /* radius/zoom */

<h1> hCard Brainstorming </h1>
This page is for brainstorming about various uses and details of [[hcard|hCard]].

__TOC__

== Authors ==
* [http://suda.co.uk/ Brian Suda]
* [http://tantek.com/log/ Tantek Çelik], [http://technorati.com Technorati, Inc]

== Contributors ==
* [[User:Atamido|Atamido]]
* [[User:ChrisMessina|ChrisMessina]]
* [[User:DimitriGlazkov|DimitriGlazkov]]
* ...
* ... and many others

== Problems Being Solved ==

Some of the problems that [[hcard|hCard]] helps to solve:

* having to enter business cards that go out of date (subscribe to someone's syndicated [[hcard|hCard]] instead).
* annoying "update your contact info" email from various centralized contact info services

== Examples ==

* See [[hcard-examples]], which provides several illustrative instructive examples, as well as 1:1 hCard examples for each example in [http://www.ietf.org/rfc/rfc2426.txt RFC 2426].

=== Using RFC2806 with hCard ===

[http://www.ietf.org/rfc/rfc2806.txt RFC 2806] defines the telephone scheme "tel:", "fax:" and "modem:" to handle phone communications with URIs in the same way, "mailto:" is defined for email. It's part of the list or registered schemes by IANA : [http://www.iana.org/assignments/uri-schemes Uniform Resource Identifier (URI) SCHEMES]

<pre><nowiki>
tel telephone [RFC2806]
fax fax [RFC2806]
modem modem [RFC2806]
</nowiki></pre>

It is practical to write your tel number like this.

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">+1-919-555-7878</a>
</nowiki></pre>

or even

<pre><nowiki>
<a class="tel" href="tel:+1-919-555-7878">Mr Smith's phone</a>
</nowiki></pre>

You can add support for "tel:" to your desktop and to your browser

* For Gnome, edit ~/.gnome/Gnome and add something to the URL Handlers section. (Dan Connolly uses this to get galeon to launch telnum from [http://dev.w3.org/cvsweb/2001/telagent/ telagent sources] for tel URIs)
* In Mozilla, [http://dizzy.mozdev.org/ Dizzy]
* In Internet Explorer, [http://msdn.microsoft.com/workshop/networking/pluggable/overview/overview.asp Asynchronous Pluggable Protocols]

On the CSS front… You could for example add automagically an icon. I have put the property !important for those who wants to add it to their own stylesheet in their browsers, so they know type of links when browsing.

<pre><nowiki>
a[href^="tel:"]:before {
content: '\260f ' !important;
padding-left: 20px !important; }

a[href^="mailto:"]:before {
content: '\2709 ' !important;
padding-left: 20px !important; }
</nowiki></pre>

== Encoding "modern" attributes ==

Since vCard was first established, various interactive communication technologies and addressing schemes have been widely adopted. Although there aren't specific properties for these technologies / addressing schemes, they can be captured as URLs or email addresses.

This has now been written up for the most part. See:

http://microformats.org/wiki/hcard-examples#New_Types_of_Contact_Info

Still to be addressed:

* iChat mac.com addresses, simply store "@mac.com" email addresses, e.g.
** <code><a class="email" href="mailto:steve@mac.com">...</code>
* MSN Instant Messenger, you can simple store "@hotmail.com" or "@msn.com" or "@passport.com" email addresses.
* Internet Relay Chat (IRC), use "irc:" URLs.

== CSS Styles ==
Not only can you create semantics with the hCard values, but you can add CSS styles to them as well. You are free to style the terms in any way you want, but here we can list a few ideas for how to style terms.

If you want to encode hCard data, but do NOT want to display it in the HTML code, then you can hide that tag in CSS with the following code:
<pre><nowiki>
Hidden Data
</nowiki></pre>
Transforming applications will still find the data and use it when converting hCards to vCards.

== Auto-Discovery ==
There is currently a debate over the best way to add an auto discovery link to your HTML to extract the vCard.

On the page with the hCard encoding, the best link would be as follows:
<code><nowiki> <link rel="alternate" type="text/vcard" href="..." /> </nowiki></code>
this HTML page is an alternate view of the vCard.

[[User:EtanWexler|EtanWexler]] disagrees with the value of the “type” attribute. The [http://www.iana.org/ Internet Assigned Numbers Authority] has no registration for a “text/vcard” type. The [http://www.iana.org/assignments/media-types/text/ registered and appropriate type] for vCard entities is “text/directory”, as defined in Internet RFC 2425, “[http://www.rfc-editor.org/rfc/rfc2425.txt A MIME Content-Type for Directory Information]”. RFC 2426, “[http://www.rfc-editor.org/rfc/rfc2425.txt vCard MIME Directory Profile]”, specifies the vCard profile for “text/directory” entities, which profile the MIME/HTTP header field “Content-Type” would indicate with a “profile” parameter whose value is “VCARD”. It is unclear whether the HTML/XHTML “type” attribute allows values with parameters. On 2004-05-23, [http://bjoern.hoehrmann.de/ Björn Höhrmann] sent to the [http://www.w3.org/2002/05/html/charter HTML Working Group] a [http://www.w3.org/mid/40ccdc4d.97400945@smtp.bjoern.hoehrmann.de request for clarification] on the issue.

When on a different page, referencing that encoded page in the href would ''not'' be an alternate view of the current page. So a different rel type must be established to decribe that relationship. The ideas vary from specific to vague. The list and categories follow:
<pre><nowiki>
rel="contactinfo"
rel="profile"
rel="author"
rel='PIM'
rel='person'
rel='about'
rel='contact'
rel='hcard'
rel='microformat'
</nowiki></pre>
Example of mixing two rel types to a single page.
rel="hcard xfn"

Note: using rel="vcard" indicates a link directly to a vCard. If the document links to an hCard instead, the indication is untrue and inappropriate.

=== Auto-Discovery for XFN ===

An author will typically their XFN information on a specific page, rather than all pages. In particular, a specific page separate from the home page of their blog, and thus it would be useful to have an explicit rel value to assist in auto-discovery of XFN information.

This was suggested by Jens Alfke on 20050606 at the WWDC blogger's dinner.

== geo improvements ==

These improvements apply to both [[geo]] and [[hcard|hCard]].

I (Tantek) have seen examples of where there is a human viewable/clickable presentation of a point on a map, and the desire to include the machine readable geo information with the same element, e.g. something like:

<pre><nowiki>
<abbr class="geo" title="machine-readable-geo-info">
human readable/clickable point on a map
</abbr>
</nowiki></pre>

But to do this we must specify a syntax for putting both the latitude and longitude into the title attribute as the machine-readable-geo-info.

Fortunately, there already is a syntax for that, in vCard RFC 2426 3.4.2:
<pre>
Type value: A single structured value consisting of two float values
separated by the SEMI-COLON character (ASCII decimal 59).

Type special notes: This type specifies information related to the
global position of the object associated with the vCard. The value
specifies latitude and longitude, in that order (i.e., "LAT LON"
ordering).

...

Type example:

GEO:37.386013;-122.082932
</pre>

Thus:
<pre><nowiki>
<abbr class="geo" title="37.386013;-122.082932">
Mountain View, CA
</abbr>
</nowiki></pre>

I think this is pretty much a no-brainer, because the rules for parsing "geo" are simply altered to:

=== latitude longitude shorthand ===

If a "geo" property lacks explicit "latitude" and "longitude" subproperties, then the "geo" property is treated like any other string property (e.g. following rules for parsing <code><nowiki><abbr title></nowiki></code>, <code><nowiki><img alt></nowiki></code> etc.), where that string value has the same literal syntax as specified in RFC 2426 section 3.4.2: single structured value consisting of two float values separated by the SEMI-COLON character (ASCII decimal 59), specifying latitude and longitude, in that order.

=== geo links ===

In addition, people may publish Google Maps links like this:

<a href="http://maps.google.com/maps?q=37.386013+-122.082932">this spot</a>

(N.B. I tried and failed to get Yahoo Maps and local to do something intelligent with both "37.386013;-122.082932" and "37.386013 -122.082932").

Is it worth permitting this to be a geo as well?

I'm raising this to make sure it is considered.

However, my first guess is NO for two reasons.

# No such examples in the wild have been documented or seen as of yet (I certainly haven't seen any).
# It would involve additional parsing requirements which are almost certainly going to be site/domain specific, and encoding a particular site's query parameter syntax into a format seems like a bad idea (against principle of decentralization).

This could be mitigated if mapping services would simply accept the literal vCard GEO syntax "37.386013;-122.082932", e.g. http://maps.google.com/maps?q=37.386013;-122.082932 (which currently doesn't work) then we could make a simple rule such as for hyperlinks, parse the href attribute for a geo value at the end of the href, delimited before the value by a "=" (or perhaps "/" for services that use friendlier URLs).

=== altitude ===

Some folks have asked for "altitude" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.

=== radius/zoom ===

Kevin Marks has asked for "radius" or "zoom" as an extension to GEO. Currently we are rejecting all property/value extensions to hCard/vCard.
=== ISO6709 ===
There is a description method for geographic coordinates named [http://en.wikipedia.org/wiki/ISO_6709 ISO6709] though some differs from the notation of vCard.
It can describe latitude and the longitude. Height is optional.
If ISO6709 is used, it is likely to be able to write as follows.
<pre><nowiki>
examples
<abbr class="geo" title="+37.386013-122.082932">
Mountain View, CA
</abbr>
</nowiki></pre>

== Issues with vCard Applications ==
See [[vcard-implementations]].

== Open Questions ==

Q: since many of the components would be using CSS classes for encoding data, it is possible to MIX two different profiles. (e.g. hCard and XFN) There are no real constraints on where/how to enforce class names, these are based on the html profile, since it is difficult to associate the text within the attribute to a specific profile.

<pre><nowiki>
...
<a href="mailto:joe.smith@example.com" class="fn" rel="met">Joe Smith</a>
...
</nowiki></pre>

-- [http://suda.co.uk/ Brian Suda]

Q: Preserving White space? Should the transforming applications preserve extra white space characters? For example:
<pre><nowiki>
<a href="http://mywebsite.com/" class="fn n">
John
Q.
Public
</a>
</nowiki></pre>

When transformed into a vCard, the N property will pick apart the span tags and create the value for N correctly seperated by colons. The FN property will take a string and simply display it. There are two possible renderings for FN:
<pre><nowiki>
John Q. Public

John
Q.
Public
</nowiki></pre>

Either the white-space is preserved or it is not. Which should the transforming applications render?

-- [http://suda.co.uk/ Brian Suda]

A: The parsing application should follow the white space collapsing rules of the mime type it retrieves. I.e. if it retrieves a "text/html" document, it should do HTML white space collapsing.

-- [http://tantek.com/log/ Tantek]

Many of the Questions and Answers are relevant to both ["hCal"] and hCard.

Q: Would it be appropriate to wrap the name of the vCard owner with <dfn/>? This may give the hCard some added semantic value in the XHTML document.
<pre><nowiki>



<a class="internet" href="mailto:jfriday@host.com">
<dfn>
Joe Friday
</dfn>
</a>

+1-919-555-7878
Area Administrator, Assistant


</nowiki></pre>
-- [http://www.ben-ward.co.uk/ Ben Ward]

== Applications ==
Applications that are hCard aware or can convert hCard to vCard formats.

=== Copy hCards favelet(s) ===
* I think a Favelet would work nicely here. When you find a page that is hCard friendly, you click the favlet and you get yourself a vCard. This is done! See X2V in the implementations section of the [[hcard|hCard]] spec.

=== Distributed Commentor Icons ===

* See [http://thedredge.org/2005/06/using-hcards-in-your-blog/ using hCards in your blog] for an example of hCards used for comment authors (commentors). The system used there, "Gravatars", is a centralized site that serves commentor icons that requires login etc.

What if we gave each commentor the option of hosting their own icon?

A distributed commentor icon implementation could work like this:

# Given the URL of a commentor, look for an <code><address></code> element with classname of "vcard" at the commentor's URL. The <code><address></code> element is supposed to be the contact information for the page (see [[hcard-faq|hCard FAQ]] for more info), so this makes sense.
# Next, look for the first element inside that hcard that has a classname of "logo".
# Hopefully that element is an <code><img></code>, and if so, use its src to get the commentor's icon.
# Presto. You've got distributed commentor icons!

== Spam prevention ==
hCard uses <code>mailto:</code> links, and therefore
it automatically "inherits" the disadvantage of <code>mailto:</code> links:
These links can be easily detected by emails spiders (used by spammers).

There are ways to prevent email address detection by simple email spiders, while
still retaining full compatibility with (X)HTML applications.
One common way is to "encode" the the "m" of "mail" and "@" with character entities:

Example of the original link:
<pre><nowiki>
<a class="email" href="mailto:john.smith@example.com">john.smith@example.com</a>
</nowiki></pre>

Example of the "encoded" link:
<pre><nowiki>
<a class="e&#109;ail" href="&#109;ailto:john.smith&#064;example.com">john.smith&#064;example.com</a>
</nowiki></pre>

Simple email spiders which do not do character entity decoding will therefore not be able to find your email address.

''Note:'' Perhaps there are or will be email spiders which can decode entities, so the this technique will only help with some (cheap) email spiders.
(See also: http://rbach.priv.at/Misc/2005/EmailSpiderTest)

== Tutorials ==
* How to hCard encode entries in Popular blog software.
* Good reasons to publish your hCard
** as a business, get people to put you in their address book so they'll find you later
** as a business with an email list, get people to add you (with email address) to their address book so that your email list works via whitelisting via the address book.

== Parsing ==
See separate [[hcard-parsing|hCard parsing]] page.

== Post vCard additions ==

Some have found vCard to be limiting in terms of the data/properties/fields they want to express in contact information. Some implementations use vCard extensions to express such information.

This section is for documentation of such suggested additions. Note, we will require empirical evidence of actual *real world* examples on the Web of people publishing this information as part of contact information, before considering such additions/extensions.

* altitude. From [[hcard-issues]].
** No evidence provided that contact information on the Web publishes this information.

== TODO ==

* The [[hcard-profile]] needs verification and perhaps a URL for retrieving the actual XMDP, rather than as <pre> text on a wiki page.
* Complete translating the examples from the vCard spec into hCard, and place them on a separate hCard examples page.
* Create a "rich" but realistic hCard example, say for example for a salesperson, who wants to put a whole bunch of contact information on their website in order to be found/contacted easily.
* Provide examples of how to encode instant messaging (IM) accounts. Figure out what would the mailto: or aim: URL in hCard look like in vCard. And take a look at what vCard applications do today with IM addresses.

== References ==
=== Normative References ===
* [http://www.ietf.org/rfc/rfc2426.txt RFC 2426] vCard RFC
* [http://www.ietf.org/rfc/rfc2397 RFC 2397] data URI RFC
* [http://gmpg.org/xmdp/ XMDP]
=== Informative References ===
* [http://www.imc.org/pdi/ Personal Data Interchange (PDI) at the Internet Mail Consortium]
* [http://tantek.com/log/2004/07.html#d27t1049 Markup language design notes]
* [http://tantek.com/log/2002/12.html#L20021216t2238 A Touch of Class]

== Other Implementations/Ideas ==
* [http://www.w3.org/TR/2001/NOTE-vcard-rdf-20010222/ Representing vCard Objects in RDF/XML] This could allow conversion of vCard data from XHTML to RDF and from RDF to XHTML
* It would also be possible to convert XFN and hCard to FoaF and back.

== Accepted Suggestions ==

=== Encoding Company data as a Business Card (proposal) ===

( Accepted: http://microformats.org/wiki/hcard#Organization_Contact_Info )

In the wild there are several hCards that do not currently validate because they are businesses that have omitted the "fn" property in favor of the "org" property.

Proposal: hCards representing a business or organization MUST set fn AND org to the same value. Parsers may then use this equivalence, if detected, to treat an hCard as the contact info for a business or organization rather than an individual.

Note that [http://microformats.org/wiki/vcard-implementations#organization_vs._individual Apple Address Book supports this semantic when importing vCards].

See the [http://technorati.com/about/contact.html Technorati Contact Info] for an example.

=== Implied "FN and N" Optimization (proposal) ===

Right now a parser first looks for an "n" element.

And then if no "n" is present, look for an "fn" element to use to imply an "n" element per the "implied n property" rules in the spec.

BACKGROUND:

Due to the prevalence of the use of "nicknames" or "handles" on the Web, in actual content published on the Web (e.g. authors of reviews), there has been a discussion about adding a "fn" shortcut to the "n" shortcut that used the "nickname" as a fallback.

PROPOSAL:

We should consider adding one more implied optimization after the steps documented above and that is:

If no "fn" is present either, then look for a "nickname" element to use to imply both the "fn", and the "n/given-name", leaving the "n/family-name" as empty.

This would enable "nickname" only hCards for denoting and individual on a website, which is quite common on blogs and reviews published on the Web.
* +1 [[User:Atamido|Atamido]]
* +1 [[User:ChrisMessina|ChrisMessina]] - note: multiple alternate nicknames should also be allowed
* +1 [[User:DimitriGlazkov|DimitriGlazkov]]

== Rejected Suggestions ==

Suggestion: ''The use of class="url" on an <a> tag to represent an hCard URL property is redundant. By virtue of the <a> tag you know this is a URL.''

Rejected. This is a bad suggestion because although it appears to reduce redunancy and keep things cleaner, it also creates a few problems. Without explicitly noting that this is a URL then any <a> tags within a 'vcard' would be considered a URL, for example:
<pre><nowiki>

...
<ul class="categories">
<li><a href="http://w3c.org">W3C</a></li>
</ul>
...

</nowiki></pre>

There is no way to "turn-off" the encoding of the W3C URL, whereas if "url" needed to be explicitly listed in the class attribute list, then by NOT listing it you could effectively turn it off.

location-formats

2006-05-24T02:14:00Z

Satoru: /* ISO6709 */

= Location Research =
This is a list of previous efforts at location / geographic ("Geo") data formats and protocols, as background research for developing a location format.
__TOC__

== Authors ==

* Tantek Çelik
* Bud Gibson
* Ryan King
* Eron Wright
* ...
* please add yourself if you help(ed) with this document.

= Location Examples =

== What People are Publishing ==

* links to mapping services, canonical URLs to 3rd party services like:
** Google Maps
** Map Quest
** Yahoo Maps

* human / named / legislated formats
** named places, e.g. Westin St. Francis
** addresses, including zip codes

* global/mathematical/geometrical
** Latitude / Longitude / Altitude
*** MAKE has a GeoURL button
*** Geo in RSS. Means a particular blog post is associated with a specific lat/long. Not specific about whether it means the location that the post was made from or the location was the post was about.
*** Most systems do not contemplate or support the altitude component of a coordinate. As 3D terrain mapping grows in popularity (Google Earth), expect geocoding systems to provide the altitude.

= Location Formats =

== vCard & hCard ==
vCard (RFC2426) and [[hcard]] include 'adr', a way to markup addresses. They also have a field called 'geo' for lat/long.

== UPU S42 & OASIS xNAL ==
UPU S42 is a standard for representing postal addresses. UPU, the Universal Postal Union, is the consortium of all national posts. See [http://xml.coverpages.org/ni2003-06-17-a.html UPU S42 Announcement]. xNAL, the XML Name
and Address Language, is an earlier attempt to standardize on the components of addresses developed by OASIS,
a consortium of business-process weenies. The distinction between vCard/hCard and S42/xAL/xNAL comes down to
whether the address line elements themselves are decomposed. For example, in xNAL you can specify components like
street number, street prefix directional, street name, street type, street postfix directional, subaddress type (Suite), subaddress number.

It is not always possible to conclusively determine these components from an address line, even in the US where addresses are more canonical than others. "A 4TH ST W STE 10" is a legal address line in the US. The street number and name are required (in the US) so this could be canonically decomposed as streetnumber="A", streetname="4TH", streettype="ST", postdirectional="W", subtype="STE", subtypenumber="10".

UPU S42 and OASIS xNAL standards are likely overkill for tagging general web content. However, they are important standards that should be considered in web-services involving both geocoding and reverse-geocoding. Perhaps standards
related to decomposed addresses is something that should be placed on another page.

In addition, there should be pointers to national address standards.

USPS publishes a complete list of canonical abbreviations for both streettypes and subtypes. Their publications are self-inconsistent, but it is easy to infer the correct mappings. See [http://www.usps.com/ncsc/lookups/usps_abbreviations.htm USPS Acronyms & Abbreviations]

New Zealand apparently adopted a variant of xNAL [http://www.e-government.govt.nz/docs/xnal-guidelines-1-0/index.html NZ xNAL Guidelines Release 1.0].

== ICBM ==
One comma seperated pair of lat/long <code><meta name="ICBM" content="XXX.XXXXX, XXX.XXXXX"></code>
[http://www.catb.org/~esr/jargon/html/I/ICBM-address.html]

== GeoUrl ==
* [http://geourl.org/ GeoURL]
** This seems to have a decent amount of geeky adoption, though there are lots of typical invisible metadata problems, coordinates reversed, postive instead of negative etc.
* [http://www.multimap.com/ Multimap.com] provides similar functionality to GeoUrl, searching for websites and weblogs which are geotagged or ICBM tagged, and adding them to local information databases.

== Flickr Geotags ==
* [http://steeev.f2o.org/mt/2005/05/geotagging_flickr_with_google_maps_and_greasemonkey_part_2.html Flickr GeoTagging] A Greasemonkey script for adding lat and long tags to flick pictures. He uses Google Maps to get the lat and long. Users have to enter search terms (address, etc) and then select a point on the google map. Photos are tagged with "geo:lat=xx.xxxx", "geo:lon=xx.xxxx" and "geotagged" and aggregated at [http://geobloggers.com/]
* [http://flickr.com/groups/geotagging/ A Flickr Group related to the topic]
* [http://txfx.net/2005/05/17/flickr-google-maps-geobloggers/ A visual walkthrough of the technique.]
* As of today (2005-06-01), 14k photos have been geotagged on Flickr.
* [http://mappr.com mappr], [http://brainoff.com/worldkit/flick mapping flickr] also support these geotags.
* flickr also supports [http://www.flickr.com/services/api/flickr.photos.getExif.html EXIF headers], which can be used for storing location.
* [http://beta.plazes.com plazes] also allows flickr photos to be tagged with geotags

This is somewhat of a problem though, as mechanically generated "tags" are not really tags. Including/setting Flickr "Geotags" could be considered pollution of truly user entered text, since the text of geotags is merely an encoding for a point on a map.

== Geotagging ==
* Geotagging has been employed in other hosted services: [http://brainoff.com/worldkit/delicious/ delicious], [http://worldkit.typepad.com/ Typepad], [http://blog.360.yahoo.com/blog-yRZQpvY8cq2kWXBO5ZrxEmrwsg--?p=9 Yahoo 360], [http://www.zoto.com/users/geotags/ Zoto]

But what do these references to "geotagging" mean?

== RSS ==
Several people have tried putting geographic information into RSS.
* [http://postneo.com/icbm/ This site] uses icbm coordinates and has plugins for several blogging packages.
* [http://www.blogmapper.com/ BlogMapper] - appears to be adding a namespace to RSS.
* [http://www.feedmap.net/BlogMap/ BlogMap] - picks up RSS extension and meta tag values
* [http://brainoff.com/worldkit/doc/rss.php worldKit RSS docs] - worldKit advocates and understands various flavors of geocoded RSS; particularly the "geo" namespace.
* [http://earthquake.usgs.gov/recenteqsww/rss.html USGS earthquake feed] - most widely used geocoded RSS feed
* [http://brainoff.com/worldkit/doc/polygon.php Polygons and lines in polygons] - A simple format for expressing polygons and lines is defined for worldKit
* [http://developer.yahoo.net/maps/ Yahoo Maps API] - uses "geo" ( http://www.w3.org/2003/01/geo/wgs84_pos# ) and "ymaps" ( http://api.maps.yahoo.com/Maps/V1/AnnotatedMaps.xsd ) namespaces to spatially-reference RSS as part of its API, specifically geo:lat, geo:long, ymaps:Address, ymaps:CityState, ymaps:Zip

== RDF ==
* [http://www.geosemantics.org/ Geosemantics Interest Group]
* [http://esw.w3.org/topic/GeoOnion GeoOnion] - a SW vocuabulary for relating items by distance from each other.
* [http://www.mapbureau.com/rdfmap1.0/index.html RDFMap]
* [http://esw.w3.org/topic/GeoRDF GeoRDF] similar effort to collect prior art, for an effort in interoperability between OGC standards and various lightweight geo formats.

== GML ==
[http://www.opengeospatial.org/docs/02-023r4.pdf Geographic Markup Language] provides the most complete XML descriptiono of geographic information available. Fortunately, it is also in wide-spread use, so a commonly-used subset of the 600-page specification has emerged. GML is used in the OGC WFS payload described below.

<blockquote style="background: white; border: 1px solid black; padding: 1em;">
== Open Geospatical Consortium - OGC ==
Since 1994, [http://www.opengeospatial.org/ Open Geospatial Consortium] has been developing open specifications to enable the exchange of geographic information between applications. While some GIS vendors opposed OGC initially, essentially all commercial GIS software companies have broken down their proprietary "stovepipes" by embracing OGC specifications. The recent groundswell of ajax mapping applications can benefit tremendously from using OGC specs.

=== WMS ===
The [http://portal.opengeospatial.org/files/?artifact_id=5316 OGC Web Map Service (WMS) specification] makes it easy to request map images from a map rendering engine, such as the [http://mapserver.gis.umn.edu/ UMN Map Server]. It is straightforward to build dynamic tiling ("slippy map") ajax applications that pull in OGC map tiles. At Where 2.0, [http://www.metacarta.com MetaCarta] demonstrated such an OGC-capable ajax GIS client. The portal map providers (yahoo/gmaps/msn/map quest) do not yet offer WMS interfaces, so someone should wrap their proprietary interfaces in a WMS wrapper to encourage them :-)

=== WCS ===

Web Coverage Service extends WMS to enable attribute information about large area overview maps.

=== WFS ===
The [https://portal.opengeospatial.org/files/?artifact_id=8339 OGC Web Feature Service (WFS) specification] is the best way to express geographic information about Web content. It is more complex than the ad hoc geoURL syntax, and for good reason: it can be loaded directly into any OGC-capable GIS even if the coordinate information is in a different projection/datum or is more complex than just a point.

WFS provides a robust means of querying for geographic entities, such as points, polygons, and more complex feature types. One can define new feature types simply by describing them. One can even specify the visual appearance of the geographic features using the [https://portal.opengeospatial.org/files/?artifact_id=1188 OGC Styled Layer Description (SLD) specification].

WFS is to vector map data, as WMS is to raster map data.

Geographic search results, such as the yellow page information from the portals, could be presented in WFS. John Battelle commented that RSS forces publishers to attach their business model to their content, instead of to the web site holding the content, so that they can make money no matter where their content flows. The search portals will probably be forced to do the same, e.g. putting click-through ads in the RSS search results or WFS yellow page results, so that even when you display them in your customized ajax mapping application, the portal publishing the search results can still make money.

</blockquote>

== Google ==
=== Google Earth XML ===
20050629 at Where 2.0 conference:
"Google Earth has an XML schema for describing a place on the earth. Will be releasing today or tomorrow."
- John Hanke of Google/Keyhole.
Official KML [http://www.keyhole.com/kml/kml_doc.html Docs] and [http://www.keyhole.com/kml/kml_tut.html Tutorial]

[http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/16076/an/khGlobe/page/0#16076 Reverse-Engineered KML Schema] (deprecated now that KML 2.0 is officially released)

Note that KML supports the ''altitude'' component of a coordinate to support 3D terrain.

== NMEA ==

[http://www.gpsinformation.org/dale/nmea.htmhttp://www.gpsinformation.org/dale/nmea.htm Standard and Proprietary NMEA Sentances]

== Wikipedia ==

[http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Geo:Coordinates in Wikipedia Project]

== ISO6709 ==
[http://en.wikipedia.org/wiki/ISO_6709 : ISO6709 Alpha-numerical representation of Latitude,Longitude,(Altitude)]

== Other Formats ==

* GPX = GPS XML format
* [http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Wikipedia markup styles]
* [http://openguides.org/ OpenGuides] and [http://b.evnt.org evnt] are both looking into real-world/folksonomic location name mappings

= Location APIs =

== Google Maps API ==
* [http://www.google.com/apis/maps/ Google Maps API documentation]

== Yahoo Maps API ==
* [http://developer.yahoo.net/maps/ Yahoo Maps API documentation]

= Location Data, Tools and Sites =

== Address2Coordinates ==
These systems are freely available sources of address to lat/long mappings (US only). The first few are based on US Census data, so they might be up to date.
* [http://www.census.gov/geo/www/tiger/ TIGER]
* [http://www.itl.nist.gov/fipspubs/55new/nav-top-fr.htm FIPS]
* [http://geocoder.us/ geocoder]
* You can get coordinates from UK post-codes from [http://www.streetmap.co.uk streetmap]
* Worldwide city level location data (over 4 million entries) is available from the [http://earth-info.nga.mil/gns/html/ GNS]. This is accessible as a REST service from the [http://brainoff.com/geocoder/ worldkit geocoder]
* [http://www.mysociety.org/?p=83 mysociety.org] is providing an interesting name-based location look-up services. The results are returned as a CSV file!   For instance, the query [http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale] returns

<pre>
"Name","In","Near","Latitude","Longitude","State","Score"
"Sunnyvale","Santa Clara County","","37.36889","-122.03528","CA","100"
</pre>
but with a mime-type (text/csv) that browsers don't understand.

== A2B ==
[http://www.a2b.cc/ A2B] is a location based search engine. Lat and long only. Seems to pick stuff up from geo meta tags. Pages can either be manually entered or [http://www.a2b.cc/help-searching-addurl-blogping.a2b pinged]. They support lat/long and ICBM meta tags.

== Plazes ==
[http://plazes.com Plazes] is a system that does geo-info based on the network access point that the user's computer is connected to. They use tagging to identify locations.

== Mapping Sites ==
* [http://www.multimap.com Multimap]
* [http://maps.google.com Google Maps]
* [http://www.mapquest.com MapQuest]
* [http://maps.yahoo.com Yahoo Maps]
* [http://www.mapblast.com MapBlast]
* [http://mapufacture.com mapufacture]

= Location Brainstorming =

A lot of was discussed and figured out at the Geo Microformat BOF at O'Reilly's Where 2.0 conference.

See the [[geo-bof-2005-06-30]] minutes/notes.

One of the thoughts that came out of BOF was the idea of [[location-tagging]].

== Conclusions on new microformats ==

The consensus conclusions from the Geo Microformat BOF at Where 2.0 was to define two new microformats to reflect the two kinds of most commonly published geo data.

* [[adr]] - for representing / marking-up / publishing address location information. "adr" is simply the [[hcard|hCard]] "adr" property and all its sub-properties.
* [[geo]] - for representing / marking-up / publishing latitude longitude location information. "geo" is simply the [[hcard|hCard]] "geo" property and all its sub-properties, with the explicitly specified datum of WGS84.

location-formats

2006-05-24T02:12:14Z

Satoru: /* Location Formats */

= Location Research =
This is a list of previous efforts at location / geographic ("Geo") data formats and protocols, as background research for developing a location format.
__TOC__

== Authors ==

* Tantek Çelik
* Bud Gibson
* Ryan King
* Eron Wright
* ...
* please add yourself if you help(ed) with this document.

= Location Examples =

== What People are Publishing ==

* links to mapping services, canonical URLs to 3rd party services like:
** Google Maps
** Map Quest
** Yahoo Maps

* human / named / legislated formats
** named places, e.g. Westin St. Francis
** addresses, including zip codes

* global/mathematical/geometrical
** Latitude / Longitude / Altitude
*** MAKE has a GeoURL button
*** Geo in RSS. Means a particular blog post is associated with a specific lat/long. Not specific about whether it means the location that the post was made from or the location was the post was about.
*** Most systems do not contemplate or support the altitude component of a coordinate. As 3D terrain mapping grows in popularity (Google Earth), expect geocoding systems to provide the altitude.

= Location Formats =

== vCard & hCard ==
vCard (RFC2426) and [[hcard]] include 'adr', a way to markup addresses. They also have a field called 'geo' for lat/long.

== UPU S42 & OASIS xNAL ==
UPU S42 is a standard for representing postal addresses. UPU, the Universal Postal Union, is the consortium of all national posts. See [http://xml.coverpages.org/ni2003-06-17-a.html UPU S42 Announcement]. xNAL, the XML Name
and Address Language, is an earlier attempt to standardize on the components of addresses developed by OASIS,
a consortium of business-process weenies. The distinction between vCard/hCard and S42/xAL/xNAL comes down to
whether the address line elements themselves are decomposed. For example, in xNAL you can specify components like
street number, street prefix directional, street name, street type, street postfix directional, subaddress type (Suite), subaddress number.

It is not always possible to conclusively determine these components from an address line, even in the US where addresses are more canonical than others. "A 4TH ST W STE 10" is a legal address line in the US. The street number and name are required (in the US) so this could be canonically decomposed as streetnumber="A", streetname="4TH", streettype="ST", postdirectional="W", subtype="STE", subtypenumber="10".

UPU S42 and OASIS xNAL standards are likely overkill for tagging general web content. However, they are important standards that should be considered in web-services involving both geocoding and reverse-geocoding. Perhaps standards
related to decomposed addresses is something that should be placed on another page.

In addition, there should be pointers to national address standards.

USPS publishes a complete list of canonical abbreviations for both streettypes and subtypes. Their publications are self-inconsistent, but it is easy to infer the correct mappings. See [http://www.usps.com/ncsc/lookups/usps_abbreviations.htm USPS Acronyms & Abbreviations]

New Zealand apparently adopted a variant of xNAL [http://www.e-government.govt.nz/docs/xnal-guidelines-1-0/index.html NZ xNAL Guidelines Release 1.0].

== ICBM ==
One comma seperated pair of lat/long <code><meta name="ICBM" content="XXX.XXXXX, XXX.XXXXX"></code>
[http://www.catb.org/~esr/jargon/html/I/ICBM-address.html]

== GeoUrl ==
* [http://geourl.org/ GeoURL]
** This seems to have a decent amount of geeky adoption, though there are lots of typical invisible metadata problems, coordinates reversed, postive instead of negative etc.
* [http://www.multimap.com/ Multimap.com] provides similar functionality to GeoUrl, searching for websites and weblogs which are geotagged or ICBM tagged, and adding them to local information databases.

== Flickr Geotags ==
* [http://steeev.f2o.org/mt/2005/05/geotagging_flickr_with_google_maps_and_greasemonkey_part_2.html Flickr GeoTagging] A Greasemonkey script for adding lat and long tags to flick pictures. He uses Google Maps to get the lat and long. Users have to enter search terms (address, etc) and then select a point on the google map. Photos are tagged with "geo:lat=xx.xxxx", "geo:lon=xx.xxxx" and "geotagged" and aggregated at [http://geobloggers.com/]
* [http://flickr.com/groups/geotagging/ A Flickr Group related to the topic]
* [http://txfx.net/2005/05/17/flickr-google-maps-geobloggers/ A visual walkthrough of the technique.]
* As of today (2005-06-01), 14k photos have been geotagged on Flickr.
* [http://mappr.com mappr], [http://brainoff.com/worldkit/flick mapping flickr] also support these geotags.
* flickr also supports [http://www.flickr.com/services/api/flickr.photos.getExif.html EXIF headers], which can be used for storing location.
* [http://beta.plazes.com plazes] also allows flickr photos to be tagged with geotags

This is somewhat of a problem though, as mechanically generated "tags" are not really tags. Including/setting Flickr "Geotags" could be considered pollution of truly user entered text, since the text of geotags is merely an encoding for a point on a map.

== Geotagging ==
* Geotagging has been employed in other hosted services: [http://brainoff.com/worldkit/delicious/ delicious], [http://worldkit.typepad.com/ Typepad], [http://blog.360.yahoo.com/blog-yRZQpvY8cq2kWXBO5ZrxEmrwsg--?p=9 Yahoo 360], [http://www.zoto.com/users/geotags/ Zoto]

But what do these references to "geotagging" mean?

== RSS ==
Several people have tried putting geographic information into RSS.
* [http://postneo.com/icbm/ This site] uses icbm coordinates and has plugins for several blogging packages.
* [http://www.blogmapper.com/ BlogMapper] - appears to be adding a namespace to RSS.
* [http://www.feedmap.net/BlogMap/ BlogMap] - picks up RSS extension and meta tag values
* [http://brainoff.com/worldkit/doc/rss.php worldKit RSS docs] - worldKit advocates and understands various flavors of geocoded RSS; particularly the "geo" namespace.
* [http://earthquake.usgs.gov/recenteqsww/rss.html USGS earthquake feed] - most widely used geocoded RSS feed
* [http://brainoff.com/worldkit/doc/polygon.php Polygons and lines in polygons] - A simple format for expressing polygons and lines is defined for worldKit
* [http://developer.yahoo.net/maps/ Yahoo Maps API] - uses "geo" ( http://www.w3.org/2003/01/geo/wgs84_pos# ) and "ymaps" ( http://api.maps.yahoo.com/Maps/V1/AnnotatedMaps.xsd ) namespaces to spatially-reference RSS as part of its API, specifically geo:lat, geo:long, ymaps:Address, ymaps:CityState, ymaps:Zip

== RDF ==
* [http://www.geosemantics.org/ Geosemantics Interest Group]
* [http://esw.w3.org/topic/GeoOnion GeoOnion] - a SW vocuabulary for relating items by distance from each other.
* [http://www.mapbureau.com/rdfmap1.0/index.html RDFMap]
* [http://esw.w3.org/topic/GeoRDF GeoRDF] similar effort to collect prior art, for an effort in interoperability between OGC standards and various lightweight geo formats.

== GML ==
[http://www.opengeospatial.org/docs/02-023r4.pdf Geographic Markup Language] provides the most complete XML descriptiono of geographic information available. Fortunately, it is also in wide-spread use, so a commonly-used subset of the 600-page specification has emerged. GML is used in the OGC WFS payload described below.

<blockquote style="background: white; border: 1px solid black; padding: 1em;">
== Open Geospatical Consortium - OGC ==
Since 1994, [http://www.opengeospatial.org/ Open Geospatial Consortium] has been developing open specifications to enable the exchange of geographic information between applications. While some GIS vendors opposed OGC initially, essentially all commercial GIS software companies have broken down their proprietary "stovepipes" by embracing OGC specifications. The recent groundswell of ajax mapping applications can benefit tremendously from using OGC specs.

=== WMS ===
The [http://portal.opengeospatial.org/files/?artifact_id=5316 OGC Web Map Service (WMS) specification] makes it easy to request map images from a map rendering engine, such as the [http://mapserver.gis.umn.edu/ UMN Map Server]. It is straightforward to build dynamic tiling ("slippy map") ajax applications that pull in OGC map tiles. At Where 2.0, [http://www.metacarta.com MetaCarta] demonstrated such an OGC-capable ajax GIS client. The portal map providers (yahoo/gmaps/msn/map quest) do not yet offer WMS interfaces, so someone should wrap their proprietary interfaces in a WMS wrapper to encourage them :-)

=== WCS ===

Web Coverage Service extends WMS to enable attribute information about large area overview maps.

=== WFS ===
The [https://portal.opengeospatial.org/files/?artifact_id=8339 OGC Web Feature Service (WFS) specification] is the best way to express geographic information about Web content. It is more complex than the ad hoc geoURL syntax, and for good reason: it can be loaded directly into any OGC-capable GIS even if the coordinate information is in a different projection/datum or is more complex than just a point.

WFS provides a robust means of querying for geographic entities, such as points, polygons, and more complex feature types. One can define new feature types simply by describing them. One can even specify the visual appearance of the geographic features using the [https://portal.opengeospatial.org/files/?artifact_id=1188 OGC Styled Layer Description (SLD) specification].

WFS is to vector map data, as WMS is to raster map data.

Geographic search results, such as the yellow page information from the portals, could be presented in WFS. John Battelle commented that RSS forces publishers to attach their business model to their content, instead of to the web site holding the content, so that they can make money no matter where their content flows. The search portals will probably be forced to do the same, e.g. putting click-through ads in the RSS search results or WFS yellow page results, so that even when you display them in your customized ajax mapping application, the portal publishing the search results can still make money.

</blockquote>

== Google ==
=== Google Earth XML ===
20050629 at Where 2.0 conference:
"Google Earth has an XML schema for describing a place on the earth. Will be releasing today or tomorrow."
- John Hanke of Google/Keyhole.
Official KML [http://www.keyhole.com/kml/kml_doc.html Docs] and [http://www.keyhole.com/kml/kml_tut.html Tutorial]

[http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/16076/an/khGlobe/page/0#16076 Reverse-Engineered KML Schema] (deprecated now that KML 2.0 is officially released)

Note that KML supports the ''altitude'' component of a coordinate to support 3D terrain.

== NMEA ==

[http://www.gpsinformation.org/dale/nmea.htmhttp://www.gpsinformation.org/dale/nmea.htm Standard and Proprietary NMEA Sentances]

== Wikipedia ==

[http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Geo:Coordinates in Wikipedia Project]

== ISO6709 ==
[http://en.wikipedia.org/wiki/ISO_6709:ISO6709 Alpha-numerical representation of Latitude,Longitude,(Altitude)]

== Other Formats ==

* GPX = GPS XML format
* [http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Wikipedia markup styles]
* [http://openguides.org/ OpenGuides] and [http://b.evnt.org evnt] are both looking into real-world/folksonomic location name mappings

= Location APIs =

== Google Maps API ==
* [http://www.google.com/apis/maps/ Google Maps API documentation]

== Yahoo Maps API ==
* [http://developer.yahoo.net/maps/ Yahoo Maps API documentation]

= Location Data, Tools and Sites =

== Address2Coordinates ==
These systems are freely available sources of address to lat/long mappings (US only). The first few are based on US Census data, so they might be up to date.
* [http://www.census.gov/geo/www/tiger/ TIGER]
* [http://www.itl.nist.gov/fipspubs/55new/nav-top-fr.htm FIPS]
* [http://geocoder.us/ geocoder]
* You can get coordinates from UK post-codes from [http://www.streetmap.co.uk streetmap]
* Worldwide city level location data (over 4 million entries) is available from the [http://earth-info.nga.mil/gns/html/ GNS]. This is accessible as a REST service from the [http://brainoff.com/geocoder/ worldkit geocoder]
* [http://www.mysociety.org/?p=83 mysociety.org] is providing an interesting name-based location look-up services. The results are returned as a CSV file!   For instance, the query [http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale] returns

<pre>
"Name","In","Near","Latitude","Longitude","State","Score"
"Sunnyvale","Santa Clara County","","37.36889","-122.03528","CA","100"
</pre>
but with a mime-type (text/csv) that browsers don't understand.

== A2B ==
[http://www.a2b.cc/ A2B] is a location based search engine. Lat and long only. Seems to pick stuff up from geo meta tags. Pages can either be manually entered or [http://www.a2b.cc/help-searching-addurl-blogping.a2b pinged]. They support lat/long and ICBM meta tags.

== Plazes ==
[http://plazes.com Plazes] is a system that does geo-info based on the network access point that the user's computer is connected to. They use tagging to identify locations.

== Mapping Sites ==
* [http://www.multimap.com Multimap]
* [http://maps.google.com Google Maps]
* [http://www.mapquest.com MapQuest]
* [http://maps.yahoo.com Yahoo Maps]
* [http://www.mapblast.com MapBlast]
* [http://mapufacture.com mapufacture]

= Location Brainstorming =

A lot of was discussed and figured out at the Geo Microformat BOF at O'Reilly's Where 2.0 conference.

See the [[geo-bof-2005-06-30]] minutes/notes.

One of the thoughts that came out of BOF was the idea of [[location-tagging]].

== Conclusions on new microformats ==

The consensus conclusions from the Geo Microformat BOF at Where 2.0 was to define two new microformats to reflect the two kinds of most commonly published geo data.

* [[adr]] - for representing / marking-up / publishing address location information. "adr" is simply the [[hcard|hCard]] "adr" property and all its sub-properties.
* [[geo]] - for representing / marking-up / publishing latitude longitude location information. "geo" is simply the [[hcard|hCard]] "geo" property and all its sub-properties, with the explicitly specified datum of WGS84.

location-formats

2006-05-24T02:09:14Z

Satoru: /* Location Formats */

= Location Research =
This is a list of previous efforts at location / geographic ("Geo") data formats and protocols, as background research for developing a location format.
__TOC__

== Authors ==

* Tantek Çelik
* Bud Gibson
* Ryan King
* Eron Wright
* ...
* please add yourself if you help(ed) with this document.

= Location Examples =

== What People are Publishing ==

* links to mapping services, canonical URLs to 3rd party services like:
** Google Maps
** Map Quest
** Yahoo Maps

* human / named / legislated formats
** named places, e.g. Westin St. Francis
** addresses, including zip codes

* global/mathematical/geometrical
** Latitude / Longitude / Altitude
*** MAKE has a GeoURL button
*** Geo in RSS. Means a particular blog post is associated with a specific lat/long. Not specific about whether it means the location that the post was made from or the location was the post was about.
*** Most systems do not contemplate or support the altitude component of a coordinate. As 3D terrain mapping grows in popularity (Google Earth), expect geocoding systems to provide the altitude.

= Location Formats =

== vCard & hCard ==
vCard (RFC2426) and [[hcard]] include 'adr', a way to markup addresses. They also have a field called 'geo' for lat/long.

== UPU S42 & OASIS xNAL ==
UPU S42 is a standard for representing postal addresses. UPU, the Universal Postal Union, is the consortium of all national posts. See [http://xml.coverpages.org/ni2003-06-17-a.html UPU S42 Announcement]. xNAL, the XML Name
and Address Language, is an earlier attempt to standardize on the components of addresses developed by OASIS,
a consortium of business-process weenies. The distinction between vCard/hCard and S42/xAL/xNAL comes down to
whether the address line elements themselves are decomposed. For example, in xNAL you can specify components like
street number, street prefix directional, street name, street type, street postfix directional, subaddress type (Suite), subaddress number.

It is not always possible to conclusively determine these components from an address line, even in the US where addresses are more canonical than others. "A 4TH ST W STE 10" is a legal address line in the US. The street number and name are required (in the US) so this could be canonically decomposed as streetnumber="A", streetname="4TH", streettype="ST", postdirectional="W", subtype="STE", subtypenumber="10".

UPU S42 and OASIS xNAL standards are likely overkill for tagging general web content. However, they are important standards that should be considered in web-services involving both geocoding and reverse-geocoding. Perhaps standards
related to decomposed addresses is something that should be placed on another page.

In addition, there should be pointers to national address standards.

USPS publishes a complete list of canonical abbreviations for both streettypes and subtypes. Their publications are self-inconsistent, but it is easy to infer the correct mappings. See [http://www.usps.com/ncsc/lookups/usps_abbreviations.htm USPS Acronyms & Abbreviations]

New Zealand apparently adopted a variant of xNAL [http://www.e-government.govt.nz/docs/xnal-guidelines-1-0/index.html NZ xNAL Guidelines Release 1.0].

== ICBM ==
One comma seperated pair of lat/long <code><meta name="ICBM" content="XXX.XXXXX, XXX.XXXXX"></code>
[http://www.catb.org/~esr/jargon/html/I/ICBM-address.html]

== GeoUrl ==
* [http://geourl.org/ GeoURL]
** This seems to have a decent amount of geeky adoption, though there are lots of typical invisible metadata problems, coordinates reversed, postive instead of negative etc.
* [http://www.multimap.com/ Multimap.com] provides similar functionality to GeoUrl, searching for websites and weblogs which are geotagged or ICBM tagged, and adding them to local information databases.

== Flickr Geotags ==
* [http://steeev.f2o.org/mt/2005/05/geotagging_flickr_with_google_maps_and_greasemonkey_part_2.html Flickr GeoTagging] A Greasemonkey script for adding lat and long tags to flick pictures. He uses Google Maps to get the lat and long. Users have to enter search terms (address, etc) and then select a point on the google map. Photos are tagged with "geo:lat=xx.xxxx", "geo:lon=xx.xxxx" and "geotagged" and aggregated at [http://geobloggers.com/]
* [http://flickr.com/groups/geotagging/ A Flickr Group related to the topic]
* [http://txfx.net/2005/05/17/flickr-google-maps-geobloggers/ A visual walkthrough of the technique.]
* As of today (2005-06-01), 14k photos have been geotagged on Flickr.
* [http://mappr.com mappr], [http://brainoff.com/worldkit/flick mapping flickr] also support these geotags.
* flickr also supports [http://www.flickr.com/services/api/flickr.photos.getExif.html EXIF headers], which can be used for storing location.
* [http://beta.plazes.com plazes] also allows flickr photos to be tagged with geotags

This is somewhat of a problem though, as mechanically generated "tags" are not really tags. Including/setting Flickr "Geotags" could be considered pollution of truly user entered text, since the text of geotags is merely an encoding for a point on a map.

== Geotagging ==
* Geotagging has been employed in other hosted services: [http://brainoff.com/worldkit/delicious/ delicious], [http://worldkit.typepad.com/ Typepad], [http://blog.360.yahoo.com/blog-yRZQpvY8cq2kWXBO5ZrxEmrwsg--?p=9 Yahoo 360], [http://www.zoto.com/users/geotags/ Zoto]

But what do these references to "geotagging" mean?

== RSS ==
Several people have tried putting geographic information into RSS.
* [http://postneo.com/icbm/ This site] uses icbm coordinates and has plugins for several blogging packages.
* [http://www.blogmapper.com/ BlogMapper] - appears to be adding a namespace to RSS.
* [http://www.feedmap.net/BlogMap/ BlogMap] - picks up RSS extension and meta tag values
* [http://brainoff.com/worldkit/doc/rss.php worldKit RSS docs] - worldKit advocates and understands various flavors of geocoded RSS; particularly the "geo" namespace.
* [http://earthquake.usgs.gov/recenteqsww/rss.html USGS earthquake feed] - most widely used geocoded RSS feed
* [http://brainoff.com/worldkit/doc/polygon.php Polygons and lines in polygons] - A simple format for expressing polygons and lines is defined for worldKit
* [http://developer.yahoo.net/maps/ Yahoo Maps API] - uses "geo" ( http://www.w3.org/2003/01/geo/wgs84_pos# ) and "ymaps" ( http://api.maps.yahoo.com/Maps/V1/AnnotatedMaps.xsd ) namespaces to spatially-reference RSS as part of its API, specifically geo:lat, geo:long, ymaps:Address, ymaps:CityState, ymaps:Zip

== RDF ==
* [http://www.geosemantics.org/ Geosemantics Interest Group]
* [http://esw.w3.org/topic/GeoOnion GeoOnion] - a SW vocuabulary for relating items by distance from each other.
* [http://www.mapbureau.com/rdfmap1.0/index.html RDFMap]
* [http://esw.w3.org/topic/GeoRDF GeoRDF] similar effort to collect prior art, for an effort in interoperability between OGC standards and various lightweight geo formats.

== GML ==
[http://www.opengeospatial.org/docs/02-023r4.pdf Geographic Markup Language] provides the most complete XML descriptiono of geographic information available. Fortunately, it is also in wide-spread use, so a commonly-used subset of the 600-page specification has emerged. GML is used in the OGC WFS payload described below.

<blockquote style="background: white; border: 1px solid black; padding: 1em;">
== Open Geospatical Consortium - OGC ==
Since 1994, [http://www.opengeospatial.org/ Open Geospatial Consortium] has been developing open specifications to enable the exchange of geographic information between applications. While some GIS vendors opposed OGC initially, essentially all commercial GIS software companies have broken down their proprietary "stovepipes" by embracing OGC specifications. The recent groundswell of ajax mapping applications can benefit tremendously from using OGC specs.

=== WMS ===
The [http://portal.opengeospatial.org/files/?artifact_id=5316 OGC Web Map Service (WMS) specification] makes it easy to request map images from a map rendering engine, such as the [http://mapserver.gis.umn.edu/ UMN Map Server]. It is straightforward to build dynamic tiling ("slippy map") ajax applications that pull in OGC map tiles. At Where 2.0, [http://www.metacarta.com MetaCarta] demonstrated such an OGC-capable ajax GIS client. The portal map providers (yahoo/gmaps/msn/map quest) do not yet offer WMS interfaces, so someone should wrap their proprietary interfaces in a WMS wrapper to encourage them :-)

=== WCS ===

Web Coverage Service extends WMS to enable attribute information about large area overview maps.

=== WFS ===
The [https://portal.opengeospatial.org/files/?artifact_id=8339 OGC Web Feature Service (WFS) specification] is the best way to express geographic information about Web content. It is more complex than the ad hoc geoURL syntax, and for good reason: it can be loaded directly into any OGC-capable GIS even if the coordinate information is in a different projection/datum or is more complex than just a point.

WFS provides a robust means of querying for geographic entities, such as points, polygons, and more complex feature types. One can define new feature types simply by describing them. One can even specify the visual appearance of the geographic features using the [https://portal.opengeospatial.org/files/?artifact_id=1188 OGC Styled Layer Description (SLD) specification].

WFS is to vector map data, as WMS is to raster map data.

Geographic search results, such as the yellow page information from the portals, could be presented in WFS. John Battelle commented that RSS forces publishers to attach their business model to their content, instead of to the web site holding the content, so that they can make money no matter where their content flows. The search portals will probably be forced to do the same, e.g. putting click-through ads in the RSS search results or WFS yellow page results, so that even when you display them in your customized ajax mapping application, the portal publishing the search results can still make money.

</blockquote>

== Google ==
=== Google Earth XML ===
20050629 at Where 2.0 conference:
"Google Earth has an XML schema for describing a place on the earth. Will be releasing today or tomorrow."
- John Hanke of Google/Keyhole.
Official KML [http://www.keyhole.com/kml/kml_doc.html Docs] and [http://www.keyhole.com/kml/kml_tut.html Tutorial]

[http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/16076/an/khGlobe/page/0#16076 Reverse-Engineered KML Schema] (deprecated now that KML 2.0 is officially released)

Note that KML supports the ''altitude'' component of a coordinate to support 3D terrain.

== NMEA ==

[http://www.gpsinformation.org/dale/nmea.htmhttp://www.gpsinformation.org/dale/nmea.htm Standard and Proprietary NMEA Sentances]

== Wikipedia ==

[http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Geo:Coordinates in Wikipedia Project]

== ISO6709 ==
[http://en.wikipedia.org/wiki/ISO_6709]

== Other Formats ==

* GPX = GPS XML format
* [http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates Wikipedia markup styles]
* [http://openguides.org/ OpenGuides] and [http://b.evnt.org evnt] are both looking into real-world/folksonomic location name mappings

= Location APIs =

== Google Maps API ==
* [http://www.google.com/apis/maps/ Google Maps API documentation]

== Yahoo Maps API ==
* [http://developer.yahoo.net/maps/ Yahoo Maps API documentation]

= Location Data, Tools and Sites =

== Address2Coordinates ==
These systems are freely available sources of address to lat/long mappings (US only). The first few are based on US Census data, so they might be up to date.
* [http://www.census.gov/geo/www/tiger/ TIGER]
* [http://www.itl.nist.gov/fipspubs/55new/nav-top-fr.htm FIPS]
* [http://geocoder.us/ geocoder]
* You can get coordinates from UK post-codes from [http://www.streetmap.co.uk streetmap]
* Worldwide city level location data (over 4 million entries) is available from the [http://earth-info.nga.mil/gns/html/ GNS]. This is accessible as a REST service from the [http://brainoff.com/geocoder/ worldkit geocoder]
* [http://www.mysociety.org/?p=83 mysociety.org] is providing an interesting name-based location look-up services. The results are returned as a CSV file!   For instance, the query [http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale http://gaze.mysociety.org/gaze-rest?f=find_places&country=US&state=CA&query=sunnyvale] returns

<pre>
"Name","In","Near","Latitude","Longitude","State","Score"
"Sunnyvale","Santa Clara County","","37.36889","-122.03528","CA","100"
</pre>
but with a mime-type (text/csv) that browsers don't understand.

== A2B ==
[http://www.a2b.cc/ A2B] is a location based search engine. Lat and long only. Seems to pick stuff up from geo meta tags. Pages can either be manually entered or [http://www.a2b.cc/help-searching-addurl-blogping.a2b pinged]. They support lat/long and ICBM meta tags.

== Plazes ==
[http://plazes.com Plazes] is a system that does geo-info based on the network access point that the user's computer is connected to. They use tagging to identify locations.

== Mapping Sites ==
* [http://www.multimap.com Multimap]
* [http://maps.google.com Google Maps]
* [http://www.mapquest.com MapQuest]
* [http://maps.yahoo.com Yahoo Maps]
* [http://www.mapblast.com MapBlast]
* [http://mapufacture.com mapufacture]

= Location Brainstorming =

A lot of was discussed and figured out at the Geo Microformat BOF at O'Reilly's Where 2.0 conference.

See the [[geo-bof-2005-06-30]] minutes/notes.

One of the thoughts that came out of BOF was the idea of [[location-tagging]].

== Conclusions on new microformats ==

The consensus conclusions from the Geo Microformat BOF at Where 2.0 was to define two new microformats to reflect the two kinds of most commonly published geo data.

* [[adr]] - for representing / marking-up / publishing address location information. "adr" is simply the [[hcard|hCard]] "adr" property and all its sub-properties.
* [[geo]] - for representing / marking-up / publishing latitude longitude location information. "geo" is simply the [[hcard|hCard]] "geo" property and all its sub-properties, with the explicitly specified datum of WGS84.